Despite considerable progress in the management of CHF, it remains a major health problem worldwide. It is estimated that there are 6-7 million people with CHF in the United States and Europe alone and approximately 1 million new patients are diagnosed with CHF every year.
Despite significant advances in the treatment of CHF using various pharmacological therapies, the quality-of-life in patients with CHF remains poor as these patients are frequently hospitalized, and heart failure in these patients is a common cause of death. In addition, there are significant long-term care costs associated with this problem.
Many patients with advanced CHF have a conduction system disease that may play a role in worsening cardiac function. One frequently noted conduction abnormality is left bundle branch block (LBBB), which is present in about 29% of patients with CHF. The presence of LBBB delays left ventricular ejection due to delayed left ventricular activation.
Pacing therapies have been introduced in an attempt to improve cardiac function in patients diagnosed with CHF. Cardiac resynchronization, in which bi-ventricular pacing is performed, has shown beneficial results in patients with CHF and LBBB. During bi-ventricular pacing, in addition to the standard right atrial and right ventricular leads, an additional lead is positioned in the coronary sinus. This additional lead is advanced into one of the branches of the coronary sinus overlaying the epicardial surface of the left ventricle. Since the lead is advanced through the coronary sinus, the potential placement positions for the lead are severely limited.
Although bi-ventricular pacing has shown beneficial results, numerous problems are associated with this technique. One such problem is the amount of time required for a physician to insert the lead into the desired location on the left ventricle. Further, the placement of the lead on the left ventricle is limited to sites that provide adequate pacing and sensing signals. Further, cannulation of the coronary sinus is often difficult due to either the rotation of the heart or the presence of an enlarged right atrium or Thebesian valve. Further, the placement of a lead on the surface of the left ventricle though the coronary sinus cannot be carried out in some patients with prior bypass surgery or with coronary sinus stenosis. Finally, the coronary sinus lead provides an oftentimes unstable placement and can become detached after installation.
Therefore, a need exists for an alternative approach that allows for the easier placement of the left ventricle lead and an apparatus for positioning such a lead in the desired location.